I was watching our Google Analytics traffic last week and noticed a sharp decline. My first thought was "My God, we've been blacklisted by Google or another search engine." I couldn't figure out why our traffic had dropped so dramatically. If it had dropped to zero I would have instantly thought the tracking script was at fault but instead it just dropped but kept counting with day to day variations.

I discovered that IE was reporting a script error and that was the clue to the mystery. We had added the JQuery library version 1.2.3 to our master page for some fancy image swapping. It turns out that this particular version of JQuery has an odd way of handling some click events and it conflicts with click handlers in Google Analytics. Apparently it doesn't happen all the time and it doesn't happen in all browsers so that's why we were still seeing some traffic records.

I pulled JQuery until it's patched and the stats popped back to normal the next day. Whew!